Overvoltage suppression device of three-phase frequency conversion AC power generation system

Abstract

The invention provides an overvoltage suppression device of a three-phase frequency conversion AC power generation system. The device comprises a generator three-phase voltage sampling circuit, an effective value computing circuit, a comparison circuit, an excitation negative voltage stabilization circuit, a CPLD processing circuit, a DSP processing circuit, an IGBT driving circuit and an energy absorption power loop. The overvoltage suppression device is matched with a voltage regulator of a generator, after overvoltage is generated, a transient overvoltage suppression sends a voltage adjustment prohibition signal, the voltage regulator of the generator no longer provides a secondary excitation current for the generator, and electricity in the generator is converted only from remaining energy in an excitation coil of a master generator. The transient overvoltage suppression device absorbs electromechanical energy in a controllable manner, thereby effectively suppressing transient overvoltage in the power grid so as to prevent power system protection caused by overvoltage, and smoothly converting the power grid voltage from transient high voltage to stable voltage so as to make thepower grid safer, more reliable and robust.

Description

technical field [0001] The invention belongs to the field of aviation frequency conversion AC power generation systems, and relates to a three-stage frequency conversion generator transient overvoltage dynamic suppression technology, in particular to an overvoltage suppression device for a three-phase frequency conversion AC power generation system. Background technique [0002] When a large-capacity load is switched or a fault occurs in a high-power variable-frequency AC power generation system, due to the protection control delay characteristics of the generator voltage regulator and the inherent response time of the contactor, the output of the generator is not yet disconnected. The voltage has seriously exceeded the voltage threshold, and a severe overvoltage occurs at the output terminal, resulting in failure of the subsequent electrical equipment or system protection. [0003] At present, transient voltage suppressors (TVS) and varistors are mainly used in engineering ...

AI Technical Summary

Problems solved by technology

TVS has fast response speed and small size, but has a large capacitance (tens to hundreds of pF), low current resistance, and only a certain number of breakdown voltages. Due to the large load current of the aero-generator, the TVS is likely to be burned out , low reliability

Varistors are not reliable due to their life times and breakdown short-circuit failure modes

The above two methods currently mainly used to suppress transient overvoltage, when applied to the harsh working environment of aviation power, generally have the problem of not meeting the high reliability requirements and having limited applicability

[0004] When the existing aeronautical generators are faced with the problem of transient overvoltage, the main method is to adjust the voltage through the generator voltage regulator to adjust the voltage to meet the voltage range required by the national military standard. If the controller cannot meet the regulation requirements, then System protection is carried out by breaking the excitation, breaking the main contactor, etc., but these methods cannot fundamentally absorb and suppress transient overvoltage quickly and effectively

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